The present invention relates to a medium transportation apparatus for transporting a medium such as a sheet and the like, an image forming apparatus including the medium transportation apparatus, and a method of assembling the medium transportation apparatus.
When a conventional image forming apparatus forms images on both side surfaces of a medium, an image forming portion of the conventional image forming apparatus forms a first image on one side surface of the medium transported thereto. Consequently, a front side surface and a backside surface of the medium are reversed at a medium reversing transportation path (a sheet reversing transportation path), and the medium is returned to a location in front of the image forming portion. In the next step, the image forming portion forms a second image on the other side surface of the medium (refer to, for example, Patent Reference).
Patent Reference: Japanese Patent Publication No. 2012-93648
In the conventional image forming apparatus disclosed in Patent Reference, the medium reversing transportation path is formed of a guide member attached to a main body structural portion of the conventional image forming apparatus. The medium reversing transportation path is configured as a transportation path for returning the medium to the location in front of the image forming portion after the image forming portion forms the first image on the medium. Accordingly, it is necessary to adjust a length of the guide member constituting the medium reversing transportation path in a horizontal direction according to a length of the image forming portion in a medium transportation direction.
For example, when the conventional image forming apparatus is a monochrome image forming apparatus having the image forming portion formed of one image forming cartridge for forming a monochrome image, it is necessary to use the guide member constituting the medium reversing transportation path and having a short length in the horizontal direction in parallel to the medium transportation direction. On the other hand, when the conventional image forming apparatus is a color image forming apparatus having the image forming portion formed of a plurality of image forming cartridges for forming a color image, the image forming portion has a length in the medium transportation direction greater than that of the image forming portion formed of one image forming cartridge for forming a monochrome image. Accordingly, it is necessary to use the guide member constituting the medium reversing transportation path and having a long length in the horizontal direction in parallel to the medium transportation direction.
Accordingly, when the two types of the conventional image forming apparatus, i.e., the monochrome image forming apparatus and the color image forming apparatus, are manufactured, it is necessary to separately prepare the two types of the guide members, i.e., the relatively short guide member for the monochrome image forming apparatus and the relatively long guide member for the color image forming apparatus. As a result, it is difficult to communize the guide members, that is, a main component constituting the medium reversing transportation path.
In order to solve the problems of the conventional image forming apparatus described above, an object of the present invention is to provide a medium transportation apparatus capable of communizing a main component constituting a medium reversing transportation path, an image forming apparatus including the medium transportation apparatus, and a method of assembling the medium transportation apparatus.
Further objects and advantages of the invention will be apparent from the following description of the invention.